0. THE TRES AMIGAS SUPERSTATION
UNITING THE NATION’S ELECTRIC POWER GRID
THE TRES AMIGAS SUPERSTATION
Class 4 Winds
April 11, 2014

1. The Location
Tres Amigas Is Ideally Situated in Eastern New Mexico Near the Borders of CO, OK and TX Serving as a Three-Way Interconnection of WECC, Eastern and ERCOT

2. Why Is Tres Amigas a SuperStation?
Tres Amigas will:
Connect the three U.S. synchronous power grids through a DC Hub that can regulate the direction and level of power flows between the grids, thereby improving the efficiency of the transmission systems in all regions
Provide economic incentives to further drive the growth of the nation’s transmission grid by expanding opportunities for efficient transactions across currently inaccessible market regions
Optimize the value of existing AC infrastructure by utilizing state of the art technology
Provide reliable and cost effective transmission services consistent with NERC standards and regional reliability requirements
Tres Amigas Will Present Significant Opportunities for the Grid

3. Why Is Tres Amigas a SuperStation?
Tres Amigas will:
Enable the buying, selling and physical delivery of electricity between participants in multiple grids
Optimize the performance of renewable energy sources by offering or creating options to firm intermittent power across a broad geographic area
Promote the development of renewable energy projects by creating an opportunity for such projects to connect to multiple high demand load areas
Enable renewable energy to follow hourly demand fluctuations throughout a large portion of North America
Integrate large scale renewable resources by providing the capability to manage real-time power fluctuations that would otherwise exceed the capability of many existing balancing authorities

4. Proposed Layout

5. Power Module “Full Bridge”
IGBT (x4)
Capacitor
Cooling plate
Gate drive
Frame
Cabling
D.C. Fuses
Lifting Frame
Insulated
supports

6. Valve Hall Interior

7. Conceptual 750 MW “Folded” VSC

8. Site Location

9. Development Plan – Phased Approach
Tres Amigas’ development strategy emphasizes a phased approach to growth, building the Superstation overtime using 750 MW VSC block increments. The phases are designed to add VSCs as needed, dictated by customer demand, as follows:

11. Funding – Tres Amigas Merchant Transmission
Unlike traditional transmission facilities, merchant transmission project owners assume all market risk. Tres Amigas has been successful in receiving significant capital through investors and private placements.
Phase II – III
1.5B
Phase I
500 M
2015
2013
Phase II-III: construction & operations, Texas node, additional HVDC converters, facilities, and business infrastructure
Preconstruction
12M
Phase I: construction & operations, East/West transmission node, including HVDC converters, buildings and business infrastructure, EMS Operations
2012
Startup 8M
Preconstruction: detailed engineering, vendor selection/contracts, product development, additional filings and detailed business plans.
2010
Startup: research, regulatory and local filings, ROW, preliminary engineering, environmental, economics and business plan.
Concept 2M
2008 11

13. Next steps Complete Anchor Tenant Negotiations Complete Financing
Finalize Transmission Line ROW Procurement
Release Contractors for Control Center, Civil Works, VSCs, Transmission Line
Groundbreaking

14. Proposed Layout

16. AC vs DC Systems
•Thomas Edison, the inventor of the light bulb and the father of electric power was a supporter and promoter of DC power •Tesla, the crow-prince of electric power industry, the inventor of multi-phase AC system, and the AC Transformer, felt that AC was the way of the future.

17. AC vs DC Systems
•Battle Ground – Chicago World’s fair- Tesla and AC Power won!!! •The last nail in the coffin for Edison and DC system - Contract for the hydro plant on Niagara River •The key advantage of AC, the ability to transform voltage and transport energy over long distances •Power electronics allowed DC to make a comeback in the form of HVDC systems

18. Advantages of HVDC Systems
Ability to transmit energy over longer distance
More power transmitting capability per ROW
Reduced losses
Voltage support at the terminal
100% controllability
Ability to provide asynchronous ties

19. Dis-advantages of HVDC Systems
A point-to-point system
Cost effective only for long distances
Lower reliability due to additional system components

20. Definitions
DC Converter – facility for converting power from AC to DC (rectifying) or DC to AC(inverting)
Line commutated converters - LCC (conventional thyristor based)
Voltage source converters - VSC (IGBT –Insulated Gate Bipolar Transistor)
Poles – term for conductor transporting the power, will be positive or negative voltage
Bipole – has a positive and negative pole
Monopole – has one positive or negative pole
Overhead or underground transmission can be used for the positive and negative poles
Earth Return – return path provided by the earth via ground electrodes
Metallic Return – return path provided by metallic conductor

21. Bi-PolE Converter Arrangement

22. VSC Symmetrical Monopole
Most common VSC configuration
for Submarine and UG Cables

23. DC Converter Stations Costs
VSC technology most frequently used for UG cables for voltages < 320 kV
VSC 500 MW converters cost approx $120M for each terminal
VSC converters cost are a little higher than LCC converters today, will continue to become more competitive in price

24. Tres Amigas SuperStation…. Uniting the Electric Grid